Electric organ



D. J. TOMCIK ELECTRIC ORGAN July 5, 1966 5 Sheets-Sheet 1 Filed April 4, 1962 .NEN

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5 Sheets-Sheet 2 D. J. TOMCIK ELECTRIC ORGAN suffe/z y Sio July 5, 1966 Filed April 4, 1962 JNVENToR. ,Danze ,7: Tonfall( 5 Sheets-Sheet 5 D. J. TOMCIK ELECTRIC ORGAN July 5, 1966 Filed April 4, 1962 July 5, 1966 13. J. ToMclK 3,259,683

ELE OTRI C ORGAN Filed April 4, 1962 5 Sheets-Sheet 4 United States Patent O 3,259,683 ELECTRIC GRGAN Daniel I. Tomcik, Buchanan, Mich., assigner to Electro- Voice, Incorporated, Buchanan, Mich., a corporation of Indiana Filed Apr. 4, 1962, Ser No. 184,972 11 Claims. (Cl. SLi-1.11)

The present application relates generally to electric organs, and more particularly to electric organs which employ electrostatic Itone generators.

Many different types of ltone generators have been employed in electric organs. The book Electronic Musical Instruments, by Richard H. Dorf, published by Radiole, 255 W. 84th St., New York y24, KN.Y. (second edition, 1958), describes the basic systems for electrically generating musical tones which have been commercially employed. The present invention relates particularly to electrostatic organs, but can be utilized with other types of organs, such as photoelectric organs.

'I'he tone generators of .an Ielectrostatic organ employ a stationary member and a rotating member each of which .are provided with confronting electrically conducting areas. A potential charge is placed across these areas so that rotation of the rotating member results in the generation of a varying electrical current. An organ employing this principle is disclosed in the patent of lean A. Dereux, entitled Electrical Musical Instruments, No. 2,959,083, dated November 8, 119601.

In the organ disclosed in the DereuX patent, the stationary member, or stator, is in the form of a disc of electrically insulating material, and the electrically conductingl areas are in the lform of circular bands of electrically conducting films which .are disposed coaXially about the disc ,and which have :areas periodically varying Lin the radial direction. The scanner -is also in the form of a disc of insulating material which is provided with electrically conducting fngers disposed on radii of the disc. Each combination of a stator and rotor contains the necessary bands and fingers to generate all of Ithe electrical signals required for vone note of the organ in all voices and for all octaves. The orga-n is provided with a keyboard for actuating key switches, and each key switch connects an electrical potential source to only one of the stator areas, and in this manner generates the electrical signal corresponding to the note of that particular key. Since each key of the keyboard must produce all of the voices of that frequency, and also may be utilized to produce notes octavely related tothe prime registration of the manual, a switching network or assembly is required between the key switches and the tone generators of the musical instrument. t

Patent application Serial No. 39,481, now abandoned, of Jean A. Dereux, entitled Keyboard and Stop Knob Operated Switch-ing System Afor an Electric Organ, discloses one approach to a switching assembly for use between key switches of an electric organ and the `tone generators of the organ. In the switching assembly disclosed in this application, a plurality of electrically conducting bars are translated by a guide bar between adjacent electrically conducting pins. This construction may readily, be achieved if pull type stops are employed for the organ, but may not be readily achieved with the more conventional lever type stops. Further, thistype of switch assembly is relatively costly .to construct, requiring conlCe siderable hand labor, and it is difficult to assemble with suiiicient precision to provide good reliability. `It is therefore one of the objects of the present invention to provide an electric organ which employs a switching assembly electrically connected between the tone generators of `the organ and the key switches thereof which is of improved construction, which may be economically manufactured, and which achieves greater reliability than the switching devices of prior electric organs.

It is also an object of the present invention -to provide an electric organ which employs electrostatic tone generators and which is provided with a simple and eiective means for obtaining a sustained or percussion eifect.

Further, it is an object of the present invention to provide a switch .assembly which is simple to construct, reliable in use, and suitable for use in electrostatic organs.

These and further objects of the present invention will be more fully understood and appreciated from a further consideration of this disclosure, particularly when viewed in the light cf the drawings, in which:

FIGUR-E l is a block schematic electrical circuit diagram of an electric organ constructed .according to the teachings of the present invention;

FIGURE 2 is a sectional View of a tone generator employed in the organ of FIGURE l;

FIGURE 3 is a Vfragmentary view -of -one of the stator plates of the tone generator of FIGURE 2;

FIGURE 4 is a fragmentary sectional view taken along the line 4 4 of FIGURE 3;

FIGURE 5 is a front elevational view of the rotor or scanner plate of the tone generator of FIGURE 2;

FIGURE 6 is a schematic electrical circuit diagram of a portion of the electric organ illustrated in FIGURES 1 through 5;

FIGURE 7 is a front elevational view of the stop switch. assembly of the electrical organ illustrated in FIGURES l through 6;

. FIGURE 8 is an elevational view of yone of the cells of the stop switch assembly of FIGURE 7;

FIGURE 9 is a plan view of one of the circuit boards of the cell of the stop switch assembly taken along the line 9-9 of FIGURE 8;

FIGURE 10` is a fragmentary and partly sectional view illustrating the mechanical linkage for one of the-actuator rods illustrated in the stop sw-itch assembly of FIGURE 7 ;v

- FIGURE 1-1 is a sectional View taken along the line 11--411 of FIGURE 10; and

FIGURE l2 is a sectional view taken along the line 12-12 of FIGURE 9.

The general organization of an electric organ which constitutes a preferred construction of the present invention and is illustrated in the iigures is set forth in the block circuit diagram of FIGURE l. A tone generator is provided for each note of one octave of the scale and also generates the same note in all other octaves, although other arrangements may also be used, these tone generators being illustrated at 10A, 10B, 10C, 10D, 10E, 10F', and 10G. It will be recognized that for simplicity, only the tone genera-tors for full tones have been illustrated and tone generators for half tones have been omitted, although a practical organ must have tone generators for each half tone also. The Aoutputs of all of :the tone generators .are connected to a common bus 12, and the input of an amplifier 114 is connected to this bus 12. The ampliiier 14 is an electronic amplifier and may be of conventional construction. A loudspeaker 16 -is connected to the output of the amplifier :14. When properly excited, the tone generators produce electrical alternating current signals which excite the amplifier )14 and are converted into sound by the loudspeaker 16.

To properly excite the tone generators, a power supply 18 must be connected to the input of these tone generators. In the particular construction, this power supply 18 is a direct current source, and it is connected to the input of the ltone generators through a stop `switch assembly 20. The stop switch assembly 20 connects the power source 18 through the key switches of one or more of the organ manuals to the tone generators. In the particular organ herein described, there are three manuals, namely the great manual 22, the swell manual 24, and the pedal clavier 26. The great manual 22 and the swell manual 24, as is conventional, have a plurality of keys mounted in a keyboard, and each of these keys actuates a key switch. The pedal clavier is a foot actuated switch device for reproducing the bass notes. Since the particular form of the stop switch assembly 20 is dictated in part by the nature of the tone generators, the tone generators will be described before further describing the stop switch assembly 20. FIGURES 2, 3 and 4 illustrate one of the tone generators in detail. 'Ihe tone generators may be those disclosed in Patent No. 2,959,083 entitled Electrical Musical Instrument issued to Jean A. Dereux, or those disclosed in patent application Serial No. 168,404 entitled Electric Organ by Jean A. Dereux and Jack E. Burcheld, tiled-February 12, 1962. Since all of the tone generators A, 10B, 10C, 10D, 10E, 10F and 10G are of similar construction, except for differences noted hereinafter, FIGURES 2 through 4 illustrate only the tone generator 10A. The tone generator 10A has a rotatable circular rotor or scanner plate 30 lixedly mounted on a shaft 32 within the housing 34 through an electrically conducting hub 35. Confronting .the rotor or scanner plate30 on either side are stator plate 36 which, in cooperation with the rotor 30, generate an electric signal'with the frequency and tone color of the desired musical one'. The signal is conducted from the rotor 30 through a second electrically conducting hub 37 insulated from the first hub 35 and a rotating to stationary connection 38, such as a mercury bath connector, to the `ampli- Iier 14.

f. The shaft 32 is journalled within a pair of ball bearings 40 in the housing 34 to make the shaft readily rotatable therein with la minimum of wobble. The shaft 32 extends beyond the housing 34 at the end opposite the mercury connection 38 and has a drive pulley 42 mounted thereon. The pulley 42 has a ball bearing 44 centrally fixed therein which is journalled to the end ofthe shaft 32. The pulley 42 may be rigidly secured -to the shaft 32, but is preferably compliantly mounted thereon. As illustrated in FIGURE 2, the pulley 42 is mounted on the shaft 32 through alleaf spring 46 which is mounted between a disc 47 secured coaxially on and rotatable with the shaft 32 and the pulley 42. Driving torque is then supplied to the shaft 32 and scanner plate 30 through the spring 46 from the pulley 42. f The spring 46 is a leaf spring, although a helical spring could be employed but transmits force less linearly. The pulley 42 is rotated at a constant rate by a motor (not shown) and an endless belt 48 which also drives the other tone generators of the organ.

The stator plates 36 of each tone generator 10 are mirror images of each other and constructed in the manner illustrated in FIGURES 3 and 4. Each stator plate 36 has an electrically insulating base 50 which may be constructed of glass, and which is provided with a plurality of electrically'conducting 'areas 52 on oneside thereof. The electrically conducting areas 52 of one stator plate 3.6 are a mirror image of the .other with corresponding areas confronting the same areas of the scanner plate 30. Each of the areas iselectrically connected to a terminal or lug 54 located at the perimeter of the base 50 by an electrically conducting strip or coating 56. Each terminal 54 is connected to a single area 52 by a single strip 56 which extends through an aperture S8 in the base 50. The base 50 is mounted with the areas S2 confronting the scanner plate 30. Each lug 54 is connected to the corresponding lug of the stator on the opposite side of the rotor 30 land to the stop switch assembly 20, as illustrated in FIGURE 2.

The scanner plate 30 is illustrated in FIGURES 2 and 5. It is also constructed of an electrically insulating base 59 which is provided with a coating 60 of electrically conducting Imaterial on both sides thereof. The base S9 is preferably of compliant material, such as sheet polyethylene, so that the scanner assumes a at planar attitude on rotation. The coating 60 is divided into a plurality of tongues 62 by means of narrow elongated voids 64 in the coating 60. These tongues are electrically connected to the hub 37, and hence to the mercury bath connection 38. Other areas of the `scanner plate 30 are grounded through the hub 35 and the shaft 32 to prevent charges from building thereon. Since :the details of tone generators of this type are fully disclosed in Patent No. 2,959,083, referred to above, the tone generators will not be further described.

The scanner plate 30 of each tone generator is rotated at a constant rate, and tones are generated by applying a potential to one or more areas 52 of the stator plates 36. The power source 18 may be connected to any one of the areas 52 of the stator plates of the :tone generators by selection of switches in the stop switch assembly 20 and one or more of the manuals 22, 24 or 26. The power source 18, in the particular construction, is a direct current source, although the present invention may also be practiced with an alternating current source, such as disclosed in Patent No. 2,147,941 to Kent. The manner in which the stop switch assembly 20 and the manuals 22,` 24 and 26 affect this connection may be more readily apparent from the schematic electrical circuit diagram of FIG- URE 6.

In FIGURE 6, one of the tone generators 10A is diagrammatically illustrated for generating all of the A notes or tones of the instrument. The A tones for all of the octaves of the instrument are generated by this tone generator 10A. In like manner, the B tones are generated by tone generator 10B for all the octaves, and the other notes of the scale for all cctaves are also generated by a separate tone generator for each note. In order to generate all of the A notes, the stator plates 36 are provided with areas located on coaxial bands disposed at different distances from the center of the plate, these areas being designated 52A, 52B, and 52C in FIG- URE 3. It is to be understood that for an instrument having 5 octaves, it is necessary either to have areas located an coxial bands disposed at five different distances from the axis of the plates, although FIGURE 6 illustrates only three such coaxial bands, or to have a band divided into a plurality of sectors of equal length which each representa different number of cycles. The tongues 62A of the scanner 30 extend closest to the center of the stator plate 30 and scans the area `52A, as well as the areas 52B and 52C. Shorter tongues, such as the tongues 62B, fail to scan the area 52C, since lthe tongue 62B does not extend sufliciently close to the center of the stator plate 30, but the tongue 62B will scan the area 52B. In this manner those areas positioned farthest from the center are scanned by the larger number of tongues and generate audio signals which are multiples of the signals generated from the larea 52C.

' Each stator plate 36 is also provided with an area SZAA which is loaded in the same band and at the same distance from the center of the plate as the area 52A. The area 52AA has a different shape than the area 52A and generates a different quality tone. For example, the

area 52A may generate a .ute tone, while the area v 52AA may generate a string tone. The number of different shaped areas in -a given coaxial band depends upon nected to the areas 52A, SZAA, 52B and SZBB.

the number of voices which the organ possesses. For simplicity, only two have been shown in FIGURE 6. tFlGURE 6 also illustrates the area SZBB which is in the same coaxial band as the area 52B, and hence generates the same frequency, but the area SZBB is a different voice than the area 52B.

For simplicity, vFIGURE 6 shows diagrammatically only the gre-at manual 22, although it is to be understood that the swell manual and pedal clavier are also connected to the tone generators in a manner similar to that illustrated. The -great manual 22 has a keyboard with a separate key for actuating each of a plurality of key switches designated 64A, 64B, 64C, 64D, and 64E. 'Eac-h -of thev key switches illustrated in FIGURE 6 represents the same note, namely A and does so in all tive octaves, although it is to be understood that all of the other keys are also `present in the great manual in the complete instrument. Each of the key switches is ya single pole double throw switch, and one of the stationary poles 66 of each switch 64A, 64B, 64C, 64D and 64E is connected to the positive terminal of the power source 18, which is illustrated in the form of a battery.

'I'he pole terminal 618 of the switch 64A is connected to a bus 70. switch 64B is connected to a bus 72, the pole terminal of thel switch 64C is connected to a bus 74, and the pole terminal of the switch 64D is connected to a bus '76, and the .pole terminal of the switch 64E is connected to a bus 78. Considering the switch 64C t-o actuate the A note nearest the middle C, it is to be noted that the bus 74 connected to the pole terminal of this switch is con- In addition, this bus 74 continues, and although not illustrated, connects to the areas remote from the axis of the rotor which generate the octave below 52B.

The area 512A is connected to the bus 74 through a resistor 80A connected in series with a switch 82A. The area SZAAis connected to the bus 74 through a resistor 80AA connected in series with a switch 84AA. The area 52B is connected to the bus 74 through -a resistor 80B and a switch 86B connected in series. The area 523B is connected to the bus 74 through a resistor 801313 connected in series with a switch SSBB.

Even though the switch `64C is closed, that is, the pole terminal `68 is connected to the stationary terminal 66, no signal will be produced by lche tone generator A unless one of the voicing switches is closed, those heretofore mentioned being the switches 82A, 84AA, 86BA and S8BB. The switches 82A and 84AA represent difterent voices of the same frequency, for example, the iiute and the string voices one octave below the fundamental frequency of middle A, namely the 16 foot voices. The switches `861B and SSBB may represent the flute and string voices of the fundamental frequency, namely the 8 foot tones. The switch 86B is ganged with other voice stop switches, such as 86A, to produce the 8 foot tiute tones of the organ. In like manner, the switch 82A is ganged with other voice switches, such as 82B, to produce the 16 foot ylute tones of the organ. The 4 foot flute tones of the organ are produced by another set of ganged switches 90A, and 90B connected in a manner similar to t-he voice switches already described. The switch 88'BB is gangedV with a switch 88AA for the production of the 8 foot string tones of the organ. In like manner, a Switch 90AA is ganged with a switch 90BB to produce the string 4 foot tones, and the switch 84AA is ganged with a switch 84BB to produce the 16 foot tones of the organ. It is to be understood that each of the flute areas of the tone generator 10A is provided with a switch ganged to the switch 90A for the 4 foot voice, ganged to the switch =86A for the 8 foot voice, and ganged to the switch 82A for the 16 foot voice. In like manner, each of the string areas is ganged to the switch 90AA for the 4 foot voice, ganged to the switch SSAA for the 8 foot voice, and ganged to the switch 84AA for the 16 foot voice.

In like manner, the pole terminal of the Each of the areas 52 is also connected to the negative terminal of the power source 18 through a capaictor 94 and a resistor 96 connected in parallel. The capacitor 94 and the resistor 96 provide the proper time constant to achieve the desired attack and decay rates for the instrument upon closing and opening of the key switches 64 of the manual. Also, the values of the shunt re- -sistance 96 and series resistance, such as 80A, determine the potential applied to a given area 52, and hence the level of the note produced compared to other areas. In addition, these resistances contribute to the voicing of the organ.

The second stationary contact 98 of the key switch 64A is connected to the negative terminal of the power source 18 through a switch 100A. In like manner, the second stationary contact 98 of the key switch 64B is connected to the negative terminal of the power source 18 through a switch 100B, and the stationary contacts 98 of the key switches 64C, 64D and 64E are connected to the negative terminal of the power source 18 through switches 100C, 100D and 100B, respectively. The switches of 100A, 100B, 100C, 100D and 100E are ganged together and form the sustained or percussion stop for the instrument. When these switches are closed, the key switches 64A, 64B, 64C, 64D and 64E are connected to the ground terminal in their open position, thus permitting whatever charge is on the area 52 connected to a given key switch 64 to leak therefrom. As a result, when the switches 10A, 100B, 100C, 100D and 100E are closed, the tones produced decay rapidly upon opening of the key switch 64 .associated with that tone. However, when these switches are in the open position, as illustrated in FIGURE 6, the charge on the area 52 associated with a given tone is not directly connected to ground but decays through a capacitor 102 connected in series with a resistor 104. Since the pole terminal 68 of each of the key switches 64A, 64B, 64C, and 64E is connected to the ground terminal of the power source through one of the serially connected capacitors 102 and resistors 104 for the particular key involved, the desired decay rate can be achieved, thereby producing the sustained or percussion effect desired.

In the particular organ construction described throughou-t this specication, the organ is provided with 61 notes. It is thus apparent that each voice stop tab must actuate 61 switches, and the sustained switch must also actuate 61 switches. The mechanism for accomplishing these switching actions is the stop switch assembly 20, illustrated in FIGURES 7 through 12.

The stop switch assembly 20 is illustrated in elevation in FIGURE 7. All of the circuit components indicated within the dashed line designated 20 of FIGURE 6 are disposed within the stop switch assembly 20. The stop switch assembly 20 employs a plurality of circuit boards 106 which are mounted in parallel spaced relation. There is one circuit board 106 for each note of the organ, and the circuit boards are arranged in cells 108 which contain all of the circuit boards necessary for all of the octaves of a given note. One such cell is illustrated in FIGURE 8.

For illustrative purposes, one of the circuit boards is illustrated in elevation in FIGURE 9, and this circuit board, designa-ted 106A, corresponds to the circuit board illustrated in the box 106A of FIGURE 6, and constitutes one of the circuit boards of the cells 108 illustrated in FIGURE 8. This circuit board 106A has a rectangular plate or board 109 of electrically insulating material, such as epoxy resin, and employs a grounding strip 110 which traverses the board 109 parallel to the longitudinal axis thereof spaced from one edge 111 of the board 109. This grounding strip is electrically connected to a terminal 112 located adjacent to the edge 111 of the board 109. The terminal 112 is connected to the negative terminal of the power source 18, as illustrated in FIGURE 6.

The edge 113 of the board 109 opposite the edge 111 is provided with a plurality of spaced pins 114. These pins 114 are mounted on the board 109 in a line parallel to the edge 113 thereof and extend normally through the board 109. As illustrated, a leaf type contact spring 116 abuts one side -of each of the pins 114, the springs being disposed generally normal to the edge 113 of the board 109 and anchored by electrically conducting pins 118 disposed at the ends of the springs 116 opposite the edge 113 of the board 109. These springs 116 are thus in electrical contact with the pins 11'4 and the pins 118. The contact springs 116 are spring biased toward the pins 114, thus forming a normally closed switch. The switch at the far left of the board 106A illustrated in FIGURE 9, is the switch 100B for the sustained or percussion effect, illustrated in FIGURE 6, and the successive switches reading from left to right are the switches 90A, 86A, 82A, 90AA, 88AA and 84AA. The pins 118 of each of these switches forms the pole terminal thereof, and for example, the pole terminal of the switch 82A is connected to the resistor 80A and to a terminal 120 which is connected to the area 52A ofthe tone generator A. It is to be noted that the electrical conductors and components may be placed on either side of the board 109, as indicated by the dashed lines. Also, corresponding electrical elements shown in FIGURE 6 bear the same reference numbers in FIGURE 9.

The stationary contact of the switch 100B for the sustained effect is connected to the ground terminal, as illustrated in FIGURE 6 and FIGURE 9. The stationary terminal of the switch 86A is connected to a terminal 122 Iat the periphery of the board 109, and this terminal 122 is connected to key swi-tch 64B, in accordance with FIG- URE 6.

It is to be noted that the stationary terminals of switches 90A and 90AA are interconnected electrically by a connector extending beneath Ithe surface of the board 109. This connector is the bus 70 of FIGURE 6. In like manner, the bus 72 and the bus 74 are illustrated in FIGURE `9.

The contact spring 116 of the switch 100B is also connected to a terminal 124 at the perimeter of the board 109, and this terminal 124 is electrically connected to the pole terminail 98 of the key switch 64B, as shown in FIGURE 6. The key switch 64B in its open position, therefore, connects the electrically conducting area 52A of the tone generator 10A to ground through the switch 100B, thereby disconnecting the sustaining elfect from the musical instrument.

In the same manner as described above, the switches 90AA, 88AA, and 84AA are connected to a terminal 126 at the periphery of .the board 109 through resistors, such |as 80AA. The terminal 126 is electrically connected to the lelectrically conducting area 52AA of the tone generator 10A. When it is remembered that the tone generated by the electrically conducting area SZAA is of a different voice than that generated by the area 52A, and each of the swiches 90AA, 88AA and 84AA are elecrically connected to key switches differing by octaval relationships, it will be seen that closing of these switches will provide the necessary stops for the organ. The mechanism for opening these switches will be described hereafter. It should also be recognized that the circuit board 106A illustrates only two voices for the organ and employs these voices for the prime registration and one octave above and `one octave -below the prime registration of the manual. By duplicating the construction here disclosed, as many voices may .be provided as desired, a separate electrically conducting area being required in the tone generator 10A for each voice. Also, as many stops may be provided as desired for changing registrations or intercoupling generators. Further, the sustained switch 100B could be provided on a different circuit board than the one 106A here described, or more sustained switches could be provided on this circuit board 106A.

FIGURE 8 illustrates live circuit boards 106 stacked in a cell 108. Each of the circuit boards 106 is of similar construction to the circuit board 106A illustrated in FIG- URE 9, and schematically set forth in FIGURE 6, except that the number of stops and voicesirepresented' by the cir-cuit of the circuit board may be different. Also, each of the circuit boards in the cell 108 of FIGURE 8 represents the same note but a different octave thereof. Hence, FIGURE 8 represents live octaves of a particular note, such as the note A. For a particular construction of the present invention, the organ is provided with sixty-one notes, thereby requiring sixty-one circuit boards. Each cell 108 has five octaves, except for the C cell which is provided with six boards 106 since there are six octaves of Cs. Further, in this organ, a maximum of twentyve stop switches are provided, such as' switches 100B, A, 86A, 82A, etc., illustrated in FIGURE 9. These switches provide twenty-four stops for voices and registrations, and a percussion option.

-Each of the boards which forms the cell 108 of FIG- URE 8 is secured in position by a bolt 128 located in each corner of the assembly, the bolts 128 -being locked in position by nuts 130. Spacers 132 maintain the circuit boards 106 at proper distances, and the angle bracket ground strip of each circuit board 106 supports the board 109 fromsagging.

It is to be noted from FIGURE 6 that the key switch 64B is not only Iconnected to the tone generator electrically conducting areas 52A and SZAA, but also to the tone generator areas 52B and SZBB. Since the latter areas are connected to resistors, including 80B, 80BB, and other components located on the circuit board 106B, these areas generating electrical potentials one octave below that generated by the areas 52A and 52AA, it is necessary to connect the key switch 64B also to the board 106B. This is accomplished by means of connecting links 134 which extend from the board 106A to the board 106B through openings 136 inthe boards. The electrically conducting links 134 are in .the form of pins and interconnect the key switches to the boards adjacent to a given `board in `a given cell 108 in order to provide the connection to produce each voice one octave above and one octave below the prime registrations of the manual. Interconnecting links between cells may also be used to permit the circuit for one note to `be on two or more circuit boards.

FIGURE 7 illustrates only one of the twelve cells 108 of the stop switch assembly 20 for simplicity and clarity, although it is to -be understood that the other eleven cells are also included in the assembly 20. The twelve cells 108 are mounted on rods 138 which extend between a top plate and a bottom plate 142. The rods 138 are locked in position by nuts 144 located at opposite ends. The edges of each of the circuit boards 106 from which Ithe spring contacts 116 extend are disposed on a common plane which is normal to the plane of the boards 109. The spring contacts 116 are thus accessible from this side of the stop switch assembly, `and the spring contacts 116 extend a substantial distance from the edges of the boards 109, for example, .three-quarters of an inch. Also, the spring contacts 116 are disposed generally within parallel planes disposed normal to the surface of the yboards 109 `and approximately equally spaced from each other. Further, those contacts 116 disposed in a given plane al1 relate to the same stop of the organ, for example, if the switch 86A represents the prime registration of the flute, all springs contacts 116 disposed in the plane common with this switch 86A will also represent the prime registration of the ute for the sixty-one notes of the instrument.

An actuator rod 143 of electrically insulating material is rotatably mounted adjacent to each plane of the contact springs 116, these rods 143 being pivotably mounted between the botttom plate 142 and the top plate 140 of the stop switch assembly 20. As indicated in FIGURE ll, each of these rods is semi-cylindrical in shape, that is, the rods 143 have a flat surface 145 and a semicylindrical surface 146. Rotation of any one of the rods 143 from the position in which the fiat surface 145 of the rod 143 confronts the contact springs 116 disposed in the confronting plane of that rod causes the rod to contact all of these contact springs 116 and displace them from contact with the pins 114. In this manner, rotation of the electrically insulating actuator rods 143 to a position in which the llat surface 145 thereof is approximately normal to the actuator springs 116 is effective to open all of the switches confrontingwa given rod and in this manner close the stop represented by that rod.

Each of the rods 143 is actuated by .a crank mechanism 148 illustrated in FIGURE l0 and FIGURIE lll. The top plate '1'40- of the stop switch assembly 20 is provided with a circular aperture 150 confronting each of the rods l143, and a crank handle 152 with a cylindrical portion 154 is rotatably `disposed within this .aperture 150. 'The cylindrical portion 154 has a central bore i156 and an inner end 158 provided with equally spaced radial teeth 1159. The inner end i158 of the cylindrical portion 154 of the crank handle 152 mates with -the end of a cylindrical member 1'60 which also is provided with equally spaced radial teeth l161. The cylindrical member l160 is provided with a threaded indentation 162 aligned with the channel 156 of the crank handle 152, and a locking screw 162 secures the crank handle y152 and the portion 160 together. The portion 160` also has a surface 164 opposite the teeth 161, and the end ofthe semi-cylindrical rod 143 is secured to this surface 164, generally by a layer v 166 of cement.

The crank handle 152 has an offset portion `168 which is provided'with an aperture 170. rThe aperture 170 en- -gages an a-ct-uator wire 172, which is connected to a stop lever 174. The stop lever 174 is pivoted .at its center i176 in order to move the crank handle i152. In this manner, positioning of the stop lever 174 rotates Ilthe actuator member 143 to lift or move the contact springs 116 adjacent t-o that actuatorv rod 143 from the contact pins k1l14 associated with these contact springs. Since in the particular construction described throughout this specification, there .are twenty-live stop switches, twenty-live stop levers 174 are also required.

The actuator rods 143 may be constructed of liberglass, which provides good electrical insulation. The ends of the rods '143 opposite the top plate )140 are of reduced diameter and joumalled within recesses 178 in the plate 142.

It is to be noted that the set screw 162 may be loosened for any rod permitting rotation between the crank Ihandle 152 and the cylindrical member 160. The meshed teeth connection between these parts permits adjustment by xed intervals between the angular position 4of these parts.

As illustrated in FIGURES 7 and l2, a stop plate 180 is also provided for the actuator rods |143 land mounted on the mounting rods 138 used to position the circuit boards 106. The stop plate 180r is disposed perpendicular to the actuator rods 143 and has an opening 182 for each actuator rod. Each opening is 'three quadrants of a circle, the fourth quadrant having a side perpendicular to the plane of the actuator rods 143. As a result, the hat surface 145 will abut one side or the other of this four-th quadrant to provide two stops 90 degrees apart. FIGURE 12 shows one rod in each of the two stop positions.

From the foregoing dis-closure, those skilled in the art will readily devise many modifications and improvements of the struc-tures hereinabove set forth. It is therefore intended that the scope of the present invention be not limited by the foregoing disclosure, but rather only by the appended claims.'

The invention claimed is:

-1. An electric lorgan comprising a plurality of tone generators for generating the tones of a musical scale, each tone generator having two parallel confronting plates, one plate being a stator plate with a plurality of electrically conducting areas thereon disposed at the same distance from the center of the plate, each of said areas representing a different voice .for .a given note and a plurality of tone generators Ihaving the same voice for other notes, the other plate .being a scanner plate with an electrically conducting area thereon, means for rotating each of the scanner plates relative to the confronting stator plate at a relatively constant rate, a source of electrical potential having first and second terminals, a keyboard having a key for each note of the musical scale, a key switch mounted adjacent to each key of the keyboard and actuatable by said key each key switch having a pole terminal and two stationary terminals, and means for electrically connecting each electrically conducting area of the stator plates in a series circuit with a key switch and the source of electrical potential including a stop switch assembly, said stop switch assembly including a plurality of flat circuit boards of electrically insulating material lhaving a straight edge, means for mounting the boards in parallel spaced relationship with the straight edge of s-aid boards on a common plane normal to the boards, a plurality of electrically conducting pins mounted on each of said boards and extending normally therefrom, said pins being disposed at spaced intervals adjacent to the straight edge of said board and each of said pins being on a common axis normal to the boards with a pin on another board, one of the pins on each board being electrically connected to the negative terminal of the power source, each of said other pins on each board being electrically connected |to the pole terminal of -a key switch, a plurality of contact springs equal in number to the number of pins mounted on .the boards, each contact vspring being mounted at one end and on a board on the opposite side of one pin from the edge of said board and extending past the pin and beyond the straight edge of -t-he board, said contact springs being generally disposed in a plurality of parallel planes normal to the boards and normal to the straight edge of the boards, the one contact .spring of each board adjacent to the one pin of said board being electrically connected to one of the stationary terminals of lone key switch, .-a decay circuit mounted on each board between said one contact spring and the negative terminal of the power source, the positive terminal of the power source being electrically connected to the other stationary terminal of each key switch, each of the other contact springs disposed in a given plane being connected to the electrically conducting areas of the stator plate of -the tone generators for reproducing the same voi-ce, and means to independently control the position of the contact springs in each of the parallel planes including an elongated electrically insulating rod positioned adjacent to the straight edge of the boards and adjacent to each plane of contact springs, said means positioning the rod in one position to place the contact sprin-gs adjacent thereto in abutment with pins and a second position -to separate said contact springs fro-rn said pins.

2. An electric organ comprising a plurality of tone generators for generating the tones of a musical scale, each tone generator having two parallel confronting plates, one plate being a stator plate with a plurality of electrically conducting areas thereon disposed in a coaxial band on the plate, each of said areas on a single tone generator representing a different voice for a given note and a plurality of tone generators having the same voice for different notes of the musical scale, the other plate of each tone generator being a scanner plate with an electrically conducting area thereon, means for rotating each of the scanner plates relative to the confronting stator plate at a relatively constant rate, a source -of electrical potential having rst and second terminals, a keyboard having a key for each note of the musical scale, a single pole double throw key switch mounted adjacent to each key of the keyboard and actuable by said key, a plurality of stop switches equal in number to the total number of areas on the stator plates, each stop switch being electrically connected between only one of said areas and the pole terminal of one of said key switches, means for ganging together the stop switches which are connected to areas of different tone .generators for generating the same voice, one of the stationary terminals of each key switch being connected to the first terminal of the potential source, a plurality of sustaining switches equal in number to the number of key switches, each sustaining switch having a tirst terminal connected to the other stationary terminal of one of the key switches and a second terminal connected to the second terminal of the potential source, a plurality of circuits comprising a resistor and capacitor connected in series equal in number to the number of areas of the stator plates, each resistor and capacitor circuit being electrically connected between one area of a stator plate and the second terminal of the potential source and means for ganging together the sustaining switches.

3. A musical instrument having a plurality of tone generators, each tone generator having two parallel confronting plates, one plate being a stator pla-te with an electrically conducting area disposed thereon and the other plate being a scanner plate with an electrically conducting area disposed thereon, means for rotating each scanner plate of the same generator relative to the stator plate at a relatively constant rate, a source of electrical potential having irst and second terminals, a first group of electrical switches, each switch of said first group having a pole terminal electrically connected to an electrically conducting area of one of said plates of one of said tone generators and two stationary terminals, one of said stationary terminals of each switch being electrically connected to the first terminal of the potential source, a second group of switches, each switch of said second group being electrically connected between the second of said stationary terminals of a switch of the first group and the second terminal of the power source, and a plurality of electrical decay circuits, each decay circuit being electrically connected between the electrically conducting area of one of the tone generators and the second terminal of the potential source.

4. A musical instrument comprising the elements of claim 3 wherein each electrical potential decay circuit comprises a capacitor and a resistor connected in series.

5. An electric organ comprising a plurality of tone generators for generating the tones of a musical scale, each tone generator having two parallel confronting plates, one plate being a stator plate with a plurality of electrically conducting areas thereon disposed in a coaxial band on the plate and the other plate being a scanner plate with an elongated electrically conducting area disposed radially thereon, means for rotating each scanner plate relative to the confronting stator plate of said tone generator at a relatively constant rate, a source of electrical potential having rst and second terminals, a keyboard having a key for each note of the musical scale, a single pole double throw key switch mounted adjacent to each key of the keyboard and actuable by said key, a plurality of stop switches equal in number to the total number of areas of the stator plates, each stop switch being electrically connected between only one of said areas and the pole terminal of one of said key switches, one of the stationary terminals of each key switch being .connected to the first terminal of the potential source, a plurality of sustaining switches equal in number tothe number of key switches, each sustaining switch having a first terminal connected to the other stationary terminal of one of the key switches and a second terminal connected to the second terminal of the potential source, and a plurality of circuits comprising a resistor and capacitor connected in series equal in number to the number of areas on the stator plates, each resistor and capacitor circuit being electrically connected between one area of a stator plates and the second terminal of the potential source.

6. A switch assembly comprising a plurality of at circuit boards, means for mounting the boards in spaced parallel relation with one edge of each board disposed on a common plane normal to the boards, an electrically conducting pin mounted on each board and extending normally therefrom, said pins being disposed on a common axis, a contact spring mounted on each of a plurality of said boards at one end on the side of the pin remote from the edge of the board, each said spring being generally norm-al to said edge of the board and confronting the pin on said board, said springs -being generally disposed in a common plane normal to the boards and extending outwardly from the edges of the boards, a straight elongated -actuator member of electrically insulating material movably mounted adjacent to the edges of the 1boards and parallel with the plane of the springs, said actuator member controlling the position of the contact springs and having a iirst position positioning the contact springs in abutment with the pins and a second position positioning the contact springs in spaced relationship to the pins.

7. A switch assembly comprising a plurality of flat circuit boards of electrically insulating material having a straigh-t edge, means for mounting the boards in parallel spaced relationship with the straight edge of said boards on a common plane normal to the boards, Ia plurality of electrically conducting pins mounted on each of said boards and extending normally therefrom, said pin-s being disposed at spaced intervals adjacent to the straight edge of said board and each of .said pins being on one of a plurality of parallel axis normal to the boards aligned with pins on other boards, a plurality of contact springs equal in number to the number of pins mounted on the boards, each contact spring being mounted at one end and on a Iboard on the opposite side of one pin from the edge of said board and extending `past the pin and beyond the s-tr-aight edge off the board, said contact springs being generally disposed in a plurality of parallel planes normal to `the boards and normal to the straight edge of the boards, and means to independently control the position of the contact springs in each of the parallel planes including an elongated electrically insulating rod positioned adjacent to the straight edge of the boards and adjacent to each plane of contact springs, said means positioning the rod in one position to place the contact springs adjacent thereto in abutment with the pins and a second position to separate said conta-ct springs from said pins.

8. A switch assembly comp-rising the elements of claim 7 wherein a plurality of circuit boards are provided with bores disposed on a common axis normal to the planes of the boards in combination with an electrically conducting rod disposed in said lbores, said rod being electrically connected to a pin on each of the bored circuit boards for electrically interconnecting the circuits of the circuit boards.

9. A switch assembly comprising the elements of claim` tact springs when the ilat side thereof is parallel with the plane of Ithe contact springs and abutting the contact springs when the iiat side thereof is normal to the plane of the contact springs.

10. A switch assembly comprising the elements of claim 9 in combination with a cran'k handle mounted on one end of the rod for controlling the rotational position of the rod, a lever adapted to be pivoted about a fulcrum point, and a mechanical coupling member extending between the crank handle and the lever to transmit forcefrom the lever to rotate the rod. Y

11. A switch assembly comprising the elements of claim 9 in combination with means for limiting rotation of the rod comprising a at plate lmounted parallel to the circuit -boards having an opening accommodating each of the References Cited by the Examiner UNITED STATES PATENTS 2,238,458 4/ 1941 Waller 200-1 12/1948 12/1953 4/1956 1l/1956` 6/1957 4/1959 1l/1959 1l/1960 14 Roth 200-1 Stilbitz 84-1.17 X Kent et al. 200-1 Stibitz 84-1.28 Ward 20G- 6 lParker ZOO-166.1 Wall 200-6 Dereux 84-128 10 ARTH'UR GAU'SS, Primary Examiner.

D. D. FORRIER, Assistant Examiner. 

1. AN ELECTRIC ORGAN COMPRISING A PLURALITY OF TONE GENERATORS FOR GENERATING THE TONES OF A MUSICAL SCALE, EACH TONE GENERATOR HAVING TWO PARALLEL CONFORMING PLATES, ONE PLATE BEING A STATOR WITH A PLURALITY OF ELECTRICAL LY CONDUCTING AREAS THEREIN DISPOSED AT THE SAME DISTANCE FROM THE CENTER OF THE PLATE, EACH OF SAID AREAS REPRESENTING A DIFFERENT VOICE FOR A GIVEN NOTE AND A PLURALITY OF TONE GENERATORS HAVING THE SAME VOICE FOR OTHER NOTES, THE OTHER PLATE BEING A SCANNER PLATE WITH AN ELECTRICALLY CONDUCTING ARE THEREON, MEANS FOR CONFRONTING EACH OF THE SCANNER PLATES RELATIVE TO THE CONFRONTING STATOR PLATE AT A RELATIVELY CONSTANT RATE, A SOURCE OF ELECTRICAL POTENTIAL HAVING FIRST AND SECOND TERMINALS, A KEYBOARD HAVING A KEY FOR EACH NOTE OF THE MUSICAL SCALE, A KEY SWITCH MOUNTED ADJACENT TO EACH KEY OF THE KEYBOARD AND ACTUATABLE BY SAID KEY EACH KEY SWITCH HAVING A POLE TERMINAL AND TWO STATIONARY TERMINALS, AND MEANS FOR ELECTRICALLY CONNECTING EACH ELECTRICALLY CONDUCTING AREA OF THE STATOR PLATES IN A SERIES CIRCUIT WITH A KEY SWITCH AND THE SOURCE OF ELECTRICALLY CONDUCTING AREA SWITCH ASSEMBLY, SAID STOP SWITCH ASSEMBLY INCLUDING A PLURALTIY OF FLAT CIRCUIT BOARD OF ELECTRICALLY INSULATING MATERIAL HAVING A STRAIGHT EDGE, MEANS FOR MOUNTING THE BOARDS IN PARALLEL SPACED RELATIONSHIP WITH THE STRAIGHT EDGE OF SAID BOARDS ON A COMMON PLANE NORMAL TO THE BOARDS, A PLURALITY OF ELECTRICALLY CONDUCTING PINS MOUNTED ON EACH OF SAID BOARD AND EXTENDING NORMALLY THEREFROM, SAID PINS BEING DISPOSED AT SPACED INTERVALS ADJACENT TO THE STRAIGHT EDGE OF SAID BOARDS AND EACH OF SAID PINS BEING IN A COMMON AXIS NORMAL TO THE BOARDS WITH A PIN ON ANOTHER BOARD, ONE OF THE PINS ON EACH BOARD BEING ELECTRICALLY CONNECTED TO THE NEGATIVE TERMINAL OF THE POWER SOURCE, EACH OF SAID OTHER PINS ON EACH BOARD BEING ELECTRICALLY CONNECTED TO THE POLE TERMINAL OF THE KEY SWITCH, A PLURALITY OF CONTACT SPRINGS EQUAL IN NUMBER TO THE NUMBER OF PINS MOUNTED ON THE BOARDS, EACH CONTACT SPRING BEING MOUNTED AT ONE END AND ON A BOARD ON THE OPPOSITE SIDE OF ONE PIN FROM THE EDGE OF SAID BOARD AND EXTENDING PAST THE PIN AND BEYOND THE STRAIGHT EDGE OF THE BOARD, SAID CONTACT SPRINGS BEING GENERALLY DISPOSED IN A PLURALITY OF PARALLEL PLANES NORMAL TO THE BOARDS AND NORMAL TO THE STRAIGHT EDGE OF THE BOARDS, THE ONE CONTACT SPRING OF EACH BOARD ADJACENT TO THE ONE PIN OF SAID BOARD BEING ELECTRICALLY CONNECTED TO ONE OF STATIONARY TERMINALS OF ONE KEY SWITCH, A DECAY CIRCUIT MOUNTED ON EACH BOARD BETWEEN SAID ONE CONTACT SPRING AND THE NEGATIVE TERMINAL OF THE POWER SOURCE, THE POSITIVE TERMINAL OF THE POWER SOURCE BEING ELECTRICALLY CONNECTED TO THE OTHER STATIONARY TERMINAL OF EACH KEY SWITCH, EACH OF THE OTHER CONTACT SPRINGS DISPOSED IN A GIVEN PLANE BEING CONNECTED TO THE ELECTRICALLY CONDUCTING AREAS OF THE STATOR PLATE OF THE TONE GENERATORS FOR REPRODUCING THE SAME VOICE, AND MEANS TO INDEPENDENTLY CONTROL THE POSITION OF THE CONTACT SPRINGS IN EACH OF THE PARALLEL PLANES INCLUDING AN ELONGATED ELECTRICALLY INSULATING ROD POSITIONED ADJACENT TO THE STRAIGHT EDGE OF THE BOARDS AND ADJACENT TO EACH PLANE OF CONTACT SPRINGS, SAID MEANS POSITIONING THE ROD IN ONE POSITION TO PLACE THE CONTACT SPRINGS ADJACENT THERETO IN ABUTMENT WITH PINS AND A SECOND POSITION TO SEPARATE SAID CONTACT SPRINGS FROM SAID PINS. 